Thymidine phosphorylase/platelet-derived endothelial cell growth factor (PD-ECGF) associated with prognosis in renal cell carcinoma

Multi-cohort validation: A comprehensive exploration of prognostic marker in clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is the most common form of RCC. It is characterized by resistance to traditional radiotherapy and chemotherapy, as well as an unfavorable clinical prognosis. Although TYMP is implicated in the advancement of tumor progression, the role of TYMP in ccRCC is still not understood. Heightened TYMP expression was identified in ccRCC through database mining and confirmed in RCC cell lines. Indeed, TYMP knockdown impacted RCC cell proliferation, migration, and invasion in vitro. TYMP showed a positive correlation with clinicopathological parameters (histological grade, pathological stage). Moreover, patients with high TYMP expression were indicative of poor prognosis in TCGA-ccRCC and external cohorts. The results of single-cell analysis showed that the distribution of TYMP was predominantly observed in monocytes and macrophages. Furthermore, there is a significant association between TYMP and immune status. Methylation analysis further elucidated the relationship between TYMP expression and multiple methylation sites. Drug sensitivity analysis unveiled potential pharmaceutical options. Additionally, mutation analyses identified an association between TYMP and the ccRCC driver genes like BAP1 and ROS1. In summary, TYMP may serve as a reliable prognostic indicator for ccRCC.

A novel definition of microvessel density in renal cell carcinoma: Angiogenesis plus vasculogenic mimicry

The present study proposed the novel concept of total microvessel density (TMVD), which is the combination of the MVD and the vasculogenic mimicry (VM) status, and evaluated its clinical significance in patients with renal cell carcinoma (RCC). For that purpose, tumor samples from 183 patients with primary RCC were examined by CD34 single or periodic acid Schiff (PAS)/CD34 dual histology staining. MVD and VM were determined according to previous literature. Clinical information (tumor stage and grade, and duration of survival) was retrieved and analyzed. Survival information and VM-associated gene expression data of patients with RCC were also retrieved from The Cancer Genome Atlas (TCGA) database and the clinical significance of each individual gene was analyzed. The results indicated that MVD exhibited obvious differences among patients with RCC; however, it was not correlated with the stage/grade or length of survival in patients with RCC. In total, 81 patients (44.3%) were CD34(−)/PAS(+) and defined as VM(+), and they had a significantly shorter survival compared with that of VM(−) patients (P=0.0002). VM was not associated with MVD. TMVD was able to distinguish between patients with high and low MVD in terms of survival, thus TMVD was better compared with MVD alone at distinguishing between patients with different survival prognoses. TCGA data analysis revealed that among the VM-associated genes, nodal growth differentiation factor, caspase-3, matrix metalloproteinase-9 and galectin-3 had a statistically significant impact on the overall/disease-free survival of patients with RCC. In conclusion, the TMVD concept may be more appropriate and sensitive compared with the MVD or VM alone in predicting tumor aggressiveness and patient survival, particularly in RCC, which is a highly vascularized, VM-rich neoplasm, and certain VM formation-associated genes are negatively associated with the survival of patients with RCC.

Vasohibin-1 is a new predictor of disease-free survival in operated patients with renal cell carcinoma

Background

Vasohibin-1 (VASH1) is an endothelium-produced angiogenesis inhibitor. Renal cell carcinoma is highly vascularised, but the significance of endogenous VASH1 in renal cell carcinoma has not been defined.

Aims

To identify VASH1 expression and its possible relationship with various clinicopathological factors and prognosis in renal cell carcinoma.

Methods

A retrospective analysis of 122 tumours obtained from 118 consecutive patients with renal cell carcinoma was performed. The expression patterns of VASH1, CD31, vascular endothelial growth factor (VEGF) and VEGF receptor type 2 (VEGFR2) were examined immunohistochemically and their relationships with clinicopathological factors were analysed.

Results

Microvessel density, VASH1 and VEGFR2 expression were significantly higher in clear cell carcinoma than in other subtypes. The VEGF expression pattern differed significantly between clear cell carcinoma and other histological subtypes. VASH1, pT factor and TNM stage were significantly associated with disease-free survival (p=0.030, p = 0.0012 and p = 0.0018, respectively). Cox models of multivariable disease-free survival analyses indicated that VASH1 and stage are independent prognostic factors (p=0.019 and p = 0.024).

Conclusions

VASH1 expression may be useful for estimating the prognosis of renal cell carcinoma. Further studies of the role of VASH1 in renal cell carcinoma involving larger sample sizes are warranted.

Presence of tumour-infiltrating FOXP3+ lymphocytes correlates with immature tumour angiogenesis in renal cell carcinomas

BACKGROUND

FOXP3+ regulatory T cells (Tregs) inhibit effector T cell functions and are implicated in tumour progression. However, together with microvessel density (MVD) they remain controversial prognostic predictors for renal cell carcinoma (RCC), and potential associations have yet to be determined. The objective of this study was to determine the prognostic significance of Tregs and MVD and their potential relationship in RCCs.

DESIGN

Paraffin-embedded tissues from 62 RCC patients were analysed using immunohistochemistry to detect FOXP3+ lymphocytes, and double immunohistochemistry to detect different microvessel types in the tumour interior, rim and normal kidney tissue, and their correlation with clinicopathological characteristics. Survival analysis was also performed.

RESULTS

The presence of FOXP3+ cells in the tumour interior or the rim showed no correlation with death from RCC and other pathological characteristics. Negative correlations were noted between the immature MVD in the tumour interior or the rim and tumour size, tumour stage and overall survival; however, there was no correlation with the nuclear grade or pathological type. A positive correlation between FOXP3+ Tregs and immature MVD (r=0.363, P=0.014) and mature MVD (r=0.383, P=0.009) was confirmed in the tumour interior. However, there was no correlation between FOXP3+ Tregs and mature MVD (r=0.281, P=0.076) or immature MVD (r=0.064, P=0.692) in the tumour rim.

CONCLUSIONS

In this study, a positive correlation between the presence of FOXP3+ Tregs and immature and mature MVD in RCC was confirmed, which suggests a link between suppression of immunity, tumour angiogenesis and poor prognosis.

Reduced expression of vasohibin-1 is associated with clinicopathological features in renal cell carcinoma

Vasohibin-1(VASH1) has recently been isolated as a novel negative feedback inhibitor of angiogenesis. Several studies have demonstrated that VASH1 plays important roles in tumor angiogenesis but the role of this angiogenic inhibitor in renal cell carcinoma (RCC) has not been elucidated until now. In this study, we investigated the expression pattern of VASH1 and the association with clinicopathological features in RCC. Expression of VASH1, hypoxia-inducible factor-1α (HIF-1α), and microvessel density (MVD, labeled by CD34) was assessed by immunohistochemistry in 46 RCC specimens and 20 adjacent nontumorous renal tissues (ANRTs). Correlation between vasohibin-1 and HIF-1α, MVD, and clinicopathological features was then investigated. In RCC, VASH1 was expressed mainly in the cytoplasm and membrane of tumor cells and partly in vascular endothelial cells. In ANRT, it was mainly expressed in the cytoplasm and membrane of renal tubular epithelial cells and partly in vascular endothelial cells and glomerular mesangial cells. The expression level of VASH1 in RCC tissue was significantly lower than that in ANRT and was significantly reduced with the increased degree of malignancy in RCC tissues. In addition, a significantly negative correlation was noted between VASH1 expression and HIF-1α expression and a significantly negative correlation was noted between VASH1 expression and MVD in RCC. Therefore, VASH1 expression is reduced and it associates with clinicopathological features in RCC. Based on our findings and the knowledge of other angiogenesis inhibitors, we postulate that VASH1 would potentially be a biomarker and a candidate for molecular targeted therapy for patients with RCC in the future.

The dual role of thymidine phosphorylase in cancer development and chemotherapy

Thymidine phosphorylase (TP), also known as "platelet-derived endothelial cell growth factor" (PD-ECGF), is an enzyme, which is upregulated in a wide variety of solid tumors including breast and colorectal cancers. TP promotes tumor growth and metastasis by preventing apoptosis and inducing angiogenesis. Elevated levels of TP are associated with tumor aggressiveness and poor prognosis. Therefore, TP inhibitors are synthesized in an attempt to prevent tumor angiogenesis and metastasis. TP is also indispensable for the activation of the extensively used 5-fluorouracil prodrug capecitabine, which is clinically used for the treatment of colon and breast cancer. Clinical trials that combine capecitabine with TP-inducing therapies (such as taxanes or radiotherapy) suggest that increasing TP expression is an adequate strategy to enhance the antitumoral efficacy of capecitabine. Thus, TP plays a dual role in cancer development and therapy: on the one hand, TP inhibitors can abrogate the tumorigenic and metastatic properties of TP; on the other, TP activity is necessary for the activation of several chemotherapeutic drugs. This duality illustrates the complexity of the role of TP in tumor progression and in the clinical response to fluoropyrimidine-based chemotherapy.

Thymidine phosphorylase as a prognostic factor in renal cell carcinoma

The purpose of the current study was to clarify further the clinicopathologic significance of thymidine phosphorylase (TP) expression in renal cell carcinoma (RCC). TP expression was evaluated with immunohistochemistry assays using monoclonal anti-TP antibody in formalin-fixed, paraffin-embedded archived specimens of 70 patients with radically operated nonmetastatic RCC (M0 by TNM classification). Semiquantitative analysis, using a scoring system for staining pattern and staining intensity was used. Univariate analysis showed that the characteristics that carried the prognostic significance for survival were age as continuous characteristic (chi-square log-rank test P = 0.0121), TP expression (P = 0.0061), histologic grade (P < 0.0001), and stage (P = 0.0244). In multivariate analysis (by Cox proportional hazards regression analysis), the factors significant for survival were age (HR 1.09; 95% CI 1.03-1.14), stage (HR 2.76; 95% CI 1.27-6.07), and histologic grade (HR 7.91; 95% CI 2.11-29.7), TP did not show independent significant value (HR 0.68; 95% CI 0.19-2.50). However, TP had strong correlation with histologic grade (P = 0.818). In conclusion, TP expression level in RCC is strongly correlated with histologic grade, which is one of well-known prognostic factors in RCC, but TP had no independent prognostic value.

Different responses to two types of 5-fluorouracil prodrugs in combination with interferon-alpha in pulmonary metastases of renal cell carcinoma: a case report

A 66-year-old Japanese man with pulmonary metastases of renal cell carcinoma found 8 months after radical nephrectomy was treated with interferon-alpha and tegafur-uracil. Since it failed to achieve tumor responses resulting in progression, he was given interferon-alpha and capecitabine. After 2 courses of combination therapy with IFN-alpha and capecitabine, significant tumor responses were obtained; two out of four pulmonary metastatic sites disappeared completely, one site showed over 50% decrease in size, and the remaining one site did no change in size. The regimen was well tolerated and toxicity observed was World Health Organization grade 1 anorexia. His disease status was maintained as stable disease by the repeated treatment with interferon-alpha and capecitabine for 17 months after tumor responses were obtained. However, tumor progression was observed thereafter. He is at present under treatment with sorafenib. This is the first case report of metastatic renal cell carcinoma, which showed different responses to two types of 5-fluorouracil prodrugs in combination with interferon-alpha, suggesting the biochemical modulation of capecitabine by interferon-alpha as a possible mechanism underlying the antitumor effect of the combination of interferon-alpha and capecitabine at the clinical setting. Present case also suggests that a combination of tumor-selective capecitabine with interferon-alpha is a potentially useful therapeutic option in metastatic renal cell carcinoma.

The cytosol activity of thymidine phosphorylase in endometrial cancer

BACKGROUND

Thymidine phosphorylase (TP) is identical with platelet-derived endothelial cell growth factor (PD-ECGF) which promotes angiogenesis. The aim of this study was to evaluate the cytosol activity of TP in tumor samples from patients with endometrial cancer.

METHODS

The activity of TP was measured by the spectrophotometric method in the cytosol of endometrial tumor samples from 43 patients. Moreover, the expression of platelet-derived endothelial cell growth factor/thymidine phosphorylase (PD-ECGF/TP) protein and microvessel density (MD) were examined in the same endometrial tumor samples by immunohistochemical staining. Normal endometrium from 16 women, treated surgically due to nononcological reasons served as a control.A relationship between the cytosol TP activity, PD-ECGF/TP protein expression, MD and clinicopathologic features was investigated.

RESULTS

A significantly higher the cytosol TP activity, PD-ECGF/TP protein expression and MD was stated in malignant tumor samples when compared to the control (samples of normal endometrium). A positive statistically significant correlation between the cytosol enzyme activity and PD-ECGF/TP protein expression and MD was found, but weaker from the remaining ones between PD-ECGF/TP protein expression and MD was observed.Besides no correlation between the cytosol TP activity, PD-ECGF/TP protein expression as well as MD and grading or histopatological type of endometrial cancer was stated.

CONCLUSION

The cytosol TP activity in endometrial cancer is significantly higher than in normal endometrium, with no relation as to the stage and grade of tumors, but correlates with the PD-ECGF/TP protein expression and MD may therefore be associated with favorable prognosis in patients treated with chemo- or radiotherapy after surgery.

High levels of thymidine phosphorylase as an independent prognostic factor in renal cell carcinoma

BACKGROUND

We investigated whether thymidine phosphorylase (TP) protein level in renal cell carcinoma (RCC) correlates with clinicopathological characteristics and clinical outcomes.

METHODS

TP protein level was measured in 116 RCC specimens and in 90 non-neoplastic kidney tissues using a sandwich-type enzyme-linked immunosolvent assay.

RESULTS

The median TP protein level in RCC tissues was 9.76-fold (range, 3.2-933.9) higher than those in non-neoplastic kidney tissues (P < 0.0001). TP protein level was correlated with T classification, histological grade and mode of infiltration. TP as a prognostic variable was studied using a logistic regression model. TP at higher levels (128 U/mg protein or greater) would play a role as an independent prognostic factor (odds ratio, 13.73; 95% confidence interval, 2.09-90.41; P = 0.0064).

CONCLUSION

TP at high levels can be regarded as an unfavorable independent prognostic factor. These results may pave a way for a novel approach to effective treatment of RCC.

Mechanisms of Disease: angiogenesis in urologic malignancies

Angiogenesis is critical for growth of tumors and their metastasis. In this article we review the literature on studies of angiogenesis pathways and markers for renal cancer, prostate cancer and bladder cancer. Overall, there is clear evidence that markers of angiogenesis and expression of angiogenic factors are associated with adverse outcomes in each of these tumor types. Relatively few angiogenic pathways have been investigated so far, although over 50 factors are known to be involved, and little has been studied on the antiangiogenic pathways and their suppression. The failing in many of the studies is small size and lack of suitable statistical analysis. Nevertheless, this review demonstrates the importance of these pathways and the need to develop selection criteria for patients who are candidates for antiangiogenic therapies. On the basis of the expression profiles reported so far, therapies that target vascular endothelial growth factor should be considered for the treatment of renal, prostate and bladder cancers. As most tumors express factors that are involved in multiple angiogenic pathways, further research is needed to determine which are coregulated and what the most common patterns are.

Transcriptional Program Associated with IFN-αResponse of Renal Cell Carcinoma

Metastatic renal cell carcinoma (RCC) is refractory to therapy; however, 10%-20% of patients respond favorably with interferon-alpha (IFN-alpha) treatment. To understand the molecular basis of response to IFN-alpha therapy, we performed global gene expression analysis of sensitive and resistant RCC cell lines in the absence and in the presence of IFN-alpha, using high-density oligonucleotide arrays to detect differentially expressed genes. In the absence of IFN-alpha, no significant differences in gene expression were observed between six sensitive and six resistant cell lines. Gene expression analysis following a time course of IFN-alpha2b treatment in one sensitive (SK-RC-17) and one resistant (SK-RC-12) cell line revealed that 484 and 354 transcripts, respectively, were modulated. A considerable number of these transcripts were similarly modulated between the two cell types that included several known targets of IFN signaling associated with antiviral and immunomodulatory activity. A further analysis of gene expression pattern in response to IFN revealed that several transcripts associated with proapoptotic function were upregulated in the sensitive cells. In the resistant cells, transcripts associated with cell survival and proliferation were induced, and key apoptotic molecules were suppressed. This study suggests that the IFN-alpha response of individual RCC tumors is determined by the expression pattern of genes in the apoptosis vs. survival and proliferation pathways rather than by alterations in expression of one or more individual genes.

Upregulation of thymidine phosphorylase in chronic glomerulonephritis and its role in tubulointerstitial injury

Chronic tubulointerstitial injury (CTI), commonly a sequel to chronic glomerulonephritis (CGN), is associated with the proliferation of new blood vessels. Angiogenesis is an essential process in chronic inflammation, and is controlled by a number of angiogenic factors including thymidine phosphorylase (TP). Knowledge of TP in renal disease is still rudimentary, and its role in CGN has not been explored. We analyzed the expression of TP by RTPCR, immunohistology and in situ hybridization in 20 human kidneys with CGN. To evaluate the degree of angiogenesis, we counted the microvessel density (MVD). MVD was significantly higher in all categories of CGN, between 19.7 +/- 7.7 and 58.9 +/- 7.5, compared to control value, 12.7 +/- 5.0 (p < 0.05). MVD was increased in areas of abundant mononuclear cell infiltration with minimal interstitial fibrosis, and decreased or absent in areas of marked fibrosis. There was a significant correlation between MVD and interstitial fibrosis (p < 0.0001). TP mRNA was upregulated for all categories of CGN. TP was strongly expressed by mononuclear inflammatory cells and in most atrophic tubules. Each MVD and interstitial volume was significantly correlated with both the number of TP+ mononuclear cells and TP+ tubular cells, respectively (p < 0.0001). We have demonstrated an upregulation of TP and increase in MVD in areas of CTI in a variety of CGN. The up-regulation of TP may contribute to angiogenesis, which may play a critical role in the progression of interstitial fibrosis in CGN.

Vascular endothelial growth factor-C (VEGF-C) expression predicts lymph node metastasis of transitional cell carcinoma of the bladder

PURPOSE

It has been found that expression of vascular endothelial growth factor-C (VEGF-C) in several carcinomas is significantly associated with angiogenesis, lymphangiogenesis and regional lymph node metastasis. However, VEGF-C expression in bladder transitional cell carcinoma (TCC) has not yet been reported. To elucidate the role of VEGF-C in bladder TCC, we examined VEGF-C expression in bladder TCC and pelvic lymph node metastasis specimens obtained from patients who underwent radical cystectomy.

METHODS

Eighty-seven patients who underwent radical cystectomy for clinically organ-confined TCC of the bladder were enrolled in the present study. No neoadjuvant treatments, except transurethral resection of the tumor, were given to these patients. The VEGF-C expressions of 87 bladder tumors and 20 pelvic lymph node metastasis specimens were examined immunohistochemically and the association between VEGF-C expression and clinicopathological factors, including angiogenesis as evaluated by microvessel density (MVD), was also examined.

RESULTS

Vascular endothelial growth factor-C expression was found in the cytoplasm of tumor cells, but not in the normal transitional epithelium. Vascular endothelial growth factor-C expression was significantly associated with the pathological T stage (P = 0.0289), pelvic lymph node metastasis (P < 0.0001), lymphatic involvement (P = 0.0008), venous involvement (P = 0.0002) and high MVD (P = 0.0043). The multivariate analysis demonstrated that VEGF-C expression and high MVD in bladder TCC were independent risk factors influencing the pelvic lymph node metastasis. Moreover, the patients with VEGF-C-positive tumors had significantly poorer prognoses than those with the VEGF-C-negative tumors (P = 0.0087) in the univariate analysis. The multivariate analysis based on Cox proportional hazard model showed that the independent prognostic factors were patient age (P = 0.0132) and pelvic lymph node metastasis (P = 0.0333).

CONCLUSION

The present study suggests that VEGF-C expression is an important predictive factor of pelvic lymph node metastasis in bladder cancer patients.

Inverse correlation of microvessel density with metastasis and prognosis in renal cell carcinoma

BACKGROUND

Although a correlation between microvessel density (MVD) and tumor aggressiveness has been established for several malignancies, the data for renal cell carcinoma (RCC) is conflicting. In order to clarify the significance of MVD, we investigated the relationships between MVD and tumor stage, grade, size, occurrence of metastasis and patient survival.

METHODS

Tumor specimens from 70 patients with primary renal cell carcinoma were examined by immunohistochemical staining for CD34.

RESULTS

There was a tendency for MVD to decrease from G1 to G3 tumors or from stage T1 to T3 tumors, although this was not statistically significant. However, the MVD for 56 non-metastatic and 14 metastatic tumors were significantly different (P = 0.005) at 109 +/- 67 and 58 +/- 35 per x400 field (mean +/- SD), respectively. Microvessel density for 36 large and 34 small tumors was also significantly different (P < 0.0001) at 48 +/- 22 and 142 +/- 54 per x400 field, respectively. The survival rate of patients with small, low grade and hypervascular tumors was significantly higher than that of patients with large (P = 0.0015), high grade (P = 0.05) or low MVD (P = 0.039) tumors. Cox proportional hazards regression analysis showed that tumor grade and size emerged as independent prognostic factors.

CONCLUSION

High MVD in RCC was inversely associated with tumor aggressiveness, but MVD was not the independent prognostic factor.

Quantitative analysis of thymidine phosphorylase and dihydropyrimidine dehydrogenase in renal cell carcinoma

OBJECTIVE

The purpose of the present study was to clarify the clinicopathological significance of both thymidine phosphorylase (TP) and dihydropyrimidine dehydrogenase (DPD) in renal cell carcinoma (RCC) based on a quantitative analysis of RCC patients.

METHODS

Levels of TP and DPD in RCC and/or uninvolved renal tissues from 65 RCC patients were measured by enzyme-linked immunosorbent assay.

RESULTS

The TP level and TP/DPD ratio were significantly higher in RCC than in adjacent uninvolved renal tissues (p < 0.0001). There was no significant difference in DPD levels between RCC and uninvolved renal tissues. The ratio of the highest to the lowest level was 623 in TP level, 28.9 in DPD level, and 985 in TP/DPD ratio. In the univariate analysis, patient's age (p = 0.04), tumor stage (p < 0.0001), tumor size (p = 0.007), TP expression (p = 0.03), and DPD expression (p = 0.04) were significantly associated with increased risk of death. Multivariate analysis showed that patient's age, tumor stage, and TP expression were independent prognostic factors.

CONCLUSIONS

TP and DPD in RCC provide prognostic information although DPD was not an independent prognostic factor. The present finding of a wide range in these enzyme expressions in RCC suggests that a certain subpopulation with a high TP/DPD ratio has potential responsiveness to fluoropyrimidines, especially 5'-deoxy-5-fluorouridine and capecitabine.

Renal cell carcinoma

Renal cell carcinoma continues to be a difficult malignancy to treat because of its ability to spread asymptomatically and its inherent resistance to conventional chemotherapy. However, molecular genetic studies bring new insights into the pathogenesis of this disorder and may provide new targets against which novel chemotherapeutic agents could be developed. Nephron-sparing surgery is also gaining wider acceptance as favorable long-term, cancer-free survival data emerge from clinical trials. For metastatic disease, cytokine therapy continues to be the mainstay of treatment despite marginal efficacy and a significant side-effect profile.

Expression of thymidine phosphorylase in primary human renal cell carcinoma by ELISA method

Thymidine phosphorylase (TP) expression in 100 paired samples of renal cell carcinoma (RCC) and normal adjacent tissue was analyzed by an ELISA method. We also investigated whether TP expression correlates with clinicopathological findings and clinical outcomes of these patients. Median TP expression was 9-fold (range, 0.5-56) higher in primary tumor than in non-cancerous renal tissue (P < 0.0001). There was a significant difference with respect to tumor venous invasion. TP expression was significantly higher in patients with such venous invasion than in those without (P = 0.018). However, there was no correlation between TP level and other clinicopathological findings and the survival curves. These results suggest that ELISA is useful for evaluating TP expression of human RCC and may provide a novel approach to therapy for patients with RCC.